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Stealth technology also termed LO technology (low observable technology) is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, missiles and satellites to make them less visible (ideally invisible) to radar, infrared, sonar and other detection methods. It corresponds to military camouflage for these parts of the electromagnetic spectrum (Multi-spectral camouflage). Development of modern stealth technologies in the United States began in 1958,〔Merlin, P.W. "(Design and Development of the Blackbird: Challenges and Lessons Learned )" ''(American Institute of Aeronautics and Astronautics )'' 47th AIAA Aerospace Sciences Meeting Including The New Horizons Forum and Aerospace Exposition 5–8 January 2009, Orlando, Florida. Accessed 2009-10-06.〕 where earlier attempts in preventing radar tracking of its U-2 spy planes during the Cold War by the Soviet Union had been unsuccessful.〔Cadirci, S. "(RF Stealth (or Low Observable) and Counter- RF Stealth Technologies: Implications of Counter- RF Stealth Solutions for Turkish Air Force )." ''Naval Postgraduate School, Monterey California, Ph.D. Thesis.'' March 2009. Accessed 6 October 2009.〕 Designers turned to develop a particular shape for planes that tended to reduce detection, by redirecting electromagnetic waves from radars. Radar-absorbent material was also tested and made to reduce or block radar signals that reflect off from the surface of planes. Such changes to shape and surface composition form stealth technology as currently used on the Northrop Grumman B-2 Spirit "Stealth Bomber".〔 The concept of stealth is to operate or hide without giving enemy forces any indications as to the presence of friendly forces. This concept was first explored through camouflage by blending into the background visual clutter. As the potency of detection and interception technologies (radar, Infra-red search and track, surface-to-air missiles, etc.) have increased over time, so too has the extent to which the design and operation of military personnel and vehicles have been affected in response. Some military uniforms are treated with chemicals to reduce their infrared signature. A modern "stealth" vehicle is designed from the outset to have a chosen spectral signature. The degree of stealth embodied in a particular design is chosen according to the predicted capabilities of projected threats. ==History== The concept of camouflage is known to predate warfare itself. Hunters have been using vegetation to conceal themselves perhaps as long as people have been hunting. In England, irregular units of gamekeepers in the 17th century were the first to adopt drab colours (common in 16th century Irish units) as a form of camouflage, following examples from the continent. During World War I, the Germans experimented with the use of ''Cellon'' (Cellulose acetate), a transparent covering material, in an attempt to reduce the visibility of military aircraft. Single examples of the Fokker E.III ''Eindecker'' fighter monoplane, the Albatros C.I two-seat observation biplane, and the Linke-Hofmann R.I prototype heavy bomber were covered with ''Cellon''. In fact, sunlight glinting from the material made the aircraft even more visible. ''Celon'' was also found to be quickly degraded both by sunlight and in-flight temperature changes so the attempt to make transparent aircraft was not proceeded with. In 1916, the British modified a small SS class airship for the purpose of night-time reconnaissance over German lines on the Western Front. Fitted with a silenced engine and a black gas bag, the craft was both invisible and inaudible from the ground but several night-time flights over German-held territory produced little useful intelligence and the idea was dropped. Diffused lighting camouflage, a shipborne form of counter-illumination camouflage, was trialled by the Royal Canadian Navy from 1941 to 1943. The concept was followed up, but for aircraft, by the Americans and the British: in 1945 a Grumman Avenger with Yehudi lights, reached from a ship before being sighted. This ability was rendered obsolete by radar. The U-boat ''U-480'' may have been the first stealth submarine. It featured an anechoic tile rubber coating, one layer of which contained circular air pockets to defeat ASDIC sonar.〔(German U-Boat: Anti Sonar Coating ). Retrieved 18 September 2012.〕 Radar absorbent rubber/semiconductor composite paints and materials (codenames: "Sumpf", "Schornsteinfeger") were used by the Kriegsmarine on submarines in World War II. Tests showed they were effective in reducing radar signatures at both short (centimetres) and long (1.5 metre) wavelengths. One of the earliest stealth aircraft was the Horten Ho 229 flying wing. It included carbon powder in the glue to absorb radio waves. Some prototypes were built, but it was never used in action.〔Myhra 2009, p. 11.〕 In 1960, the first stealth technology development program was initiated by USAF, by reducing the radar-cross-section of a Ryan Q-2C Firebee drone. This was achieved through specially designed screens over the air intake, radar-absorbent material on the fuselage and a special radar-absorbing paint. In 1958, the U.S. Central Intelligence Agency requested funding for a reconnaissance aircraft to replace the existing U-2 spy planes, and Lockheed secured contractual rights to produce it.〔 "Kelly" Johnson and his team at Lockheed's Skunk Works were assigned to produce the A-12 (or OXCART), the first of the previously top secret Blackbird series, which operated at high altitude of 70,000 to 80,000 ft and speed of Mach 3.2 to avoid radar detection. Radar absorbent material was used on U-2 spy planes, and various plane shapes designed to reduce radar detection were developed in earlier prototypes, named A1 to A11.〔 In 1964, an optimal plane shape taking into account compactness was developed for another "Blackbird", the Lockheed SR-71. This aircraft surpassed prior models in both altitude (90,000 ft) and speed (Mach 3.3).〔 The SR-71 included a number of stealthy features, notably its canted vertical stabilizers, the use of composite materials in key locations, and the overall finish in radar absorbing paint.〔("Lockheed SR-71 Blackbird." )〕 During the 1970s the U.S. Department of Defense launched project Lockheed Have Blue, with the aim of developing a stealth fighter. There was fierce bidding between Lockheed and Northrop to secure the multibillion-dollar contract. Lockheed incorporated into its bid a text written by the Soviet/Russian physicist Pyotr Ufimtsev from 1962, titled ''Method of Edge Waves in the Physical Theory of Diffraction'', Soviet Radio, Moscow, 1962. In 1971 this book was translated into English with the same title by U.S. Air Force, Foreign Technology Division.〔National Air Intelligence Center, Wright-Patterson AFB, OH, 1971. Technical Report AD 733203, Defense Technical Information Center of USA, Cameron Station, Alexandria, VA, 22304-6145, USA〕 The theory played a critical role in the design of American stealth-aircraft F-117 and B-2.〔Browne, M.W. "Two rival designers led the way to stealthy warplanes", New York Times, Sci. Times Sec., May 14, 1991.〕〔Browne, M.W. "Lockheed credits Soviet theory in design of F-117", Aviation Week Space Technology p. 27, December 1991.〕〔Rich, Ben and L. Janos, ''Skunk Works'', Little Brown, Boston, 1994.〕 Equations outlined in the paper quantified how a plane's shape would affect its detectability by radar, its radar cross-section (RCS). This was applied by Lockheed in computer simulation to design a novel shape they called the "Hopeless Diamond", a wordplay on the Hope Diamond, securing contractual rights to produce the F-117 Nighthawk starting in 1975. In 1977 Lockheed produced two 60% scale models under the Have Blue contract. The Have Blue program was a stealth technology demonstrator that lasted from 1976 to 1979. The success of Have Blue led the Air Force to create the ''Senior Trend''〔(F-117A ''Senior Trend'' )〕〔("Senior Trend" ). ''Vectorsite.net'', 1 April 2008.〕 program which developed the F-117. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Stealth technology also termed LO technology (low observable technology) is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, missiles and satellites to make them less visible (ideally invisible) to radar, infrared, sonar and other detection methods. It corresponds to military camouflage for these parts of the electromagnetic spectrum (Multi-spectral camouflage).Development of modern stealth technologies in the United States began in 1958,Merlin, P.W. "(Design and Development of the Blackbird: Challenges and Lessons Learned )" ''(American Institute of Aeronautics and Astronautics )'' 47th AIAA Aerospace Sciences Meeting Including The New Horizons Forum and Aerospace Exposition 5–8 January 2009, Orlando, Florida. Accessed 2009-10-06. where earlier attempts in preventing radar tracking of its U-2 spy planes during the Cold War by the Soviet Union had been unsuccessful.Cadirci, S. "(RF Stealth (or Low Observable) and Counter- RF Stealth Technologies: Implications of Counter- RF Stealth Solutions for Turkish Air Force )." ''Naval Postgraduate School, Monterey California, Ph.D. Thesis.'' March 2009. Accessed 6 October 2009. Designers turned to develop a particular shape for planes that tended to reduce detection, by redirecting electromagnetic waves from radars. Radar-absorbent material was also tested and made to reduce or block radar signals that reflect off from the surface of planes. Such changes to shape and surface composition form stealth technology as currently used on the Northrop Grumman B-2 Spirit "Stealth Bomber".The concept of stealth is to operate or hide without giving enemy forces any indications as to the presence of friendly forces. This concept was first explored through camouflage by blending into the background visual clutter. As the potency of detection and interception technologies (radar, Infra-red search and track, surface-to-air missiles, etc.) have increased over time, so too has the extent to which the design and operation of military personnel and vehicles have been affected in response. Some military uniforms are treated with chemicals to reduce their infrared signature. A modern "stealth" vehicle is designed from the outset to have a chosen spectral signature. The degree of stealth embodied in a particular design is chosen according to the predicted capabilities of projected threats.==History==The concept of camouflage is known to predate warfare itself. Hunters have been using vegetation to conceal themselves perhaps as long as people have been hunting. In England, irregular units of gamekeepers in the 17th century were the first to adopt drab colours (common in 16th century Irish units) as a form of camouflage, following examples from the continent.During World War I, the Germans experimented with the use of ''Cellon'' (Cellulose acetate), a transparent covering material, in an attempt to reduce the visibility of military aircraft. Single examples of the Fokker E.III ''Eindecker'' fighter monoplane, the Albatros C.I two-seat observation biplane, and the Linke-Hofmann R.I prototype heavy bomber were covered with ''Cellon''. In fact, sunlight glinting from the material made the aircraft even more visible. ''Celon'' was also found to be quickly degraded both by sunlight and in-flight temperature changes so the attempt to make transparent aircraft was not proceeded with.In 1916, the British modified a small SS class airship for the purpose of night-time reconnaissance over German lines on the Western Front. Fitted with a silenced engine and a black gas bag, the craft was both invisible and inaudible from the ground but several night-time flights over German-held territory produced little useful intelligence and the idea was dropped.Diffused lighting camouflage, a shipborne form of counter-illumination camouflage, was trialled by the Royal Canadian Navy from 1941 to 1943. The concept was followed up, but for aircraft, by the Americans and the British: in 1945 a Grumman Avenger with Yehudi lights, reached from a ship before being sighted. This ability was rendered obsolete by radar.The U-boat ''U-480'' may have been the first stealth submarine. It featured an anechoic tile rubber coating, one layer of which contained circular air pockets to defeat ASDIC sonar.(German U-Boat: Anti Sonar Coating ). Retrieved 18 September 2012. Radar absorbent rubber/semiconductor composite paints and materials (codenames: "Sumpf", "Schornsteinfeger") were used by the Kriegsmarine on submarines in World War II. Tests showed they were effective in reducing radar signatures at both short (centimetres) and long (1.5 metre) wavelengths.One of the earliest stealth aircraft was the Horten Ho 229 flying wing. It included carbon powder in the glue to absorb radio waves. Some prototypes were built, but it was never used in action.Myhra 2009, p. 11.In 1960, the first stealth technology development program was initiated by USAF, by reducing the radar-cross-section of a Ryan Q-2C Firebee drone. This was achieved through specially designed screens over the air intake, radar-absorbent material on the fuselage and a special radar-absorbing paint.In 1958, the U.S. Central Intelligence Agency requested funding for a reconnaissance aircraft to replace the existing U-2 spy planes, and Lockheed secured contractual rights to produce it. "Kelly" Johnson and his team at Lockheed's Skunk Works were assigned to produce the A-12 (or OXCART), the first of the previously top secret Blackbird series, which operated at high altitude of 70,000 to 80,000 ft and speed of Mach 3.2 to avoid radar detection. Radar absorbent material was used on U-2 spy planes, and various plane shapes designed to reduce radar detection were developed in earlier prototypes, named A1 to A11. In 1964, an optimal plane shape taking into account compactness was developed for another "Blackbird", the Lockheed SR-71. This aircraft surpassed prior models in both altitude (90,000 ft) and speed (Mach 3.3). The SR-71 included a number of stealthy features, notably its canted vertical stabilizers, the use of composite materials in key locations, and the overall finish in radar absorbing paint.("Lockheed SR-71 Blackbird." )During the 1970s the U.S. Department of Defense launched project Lockheed Have Blue, with the aim of developing a stealth fighter. There was fierce bidding between Lockheed and Northrop to secure the multibillion-dollar contract. Lockheed incorporated into its bid a text written by the Soviet/Russian physicist Pyotr Ufimtsev from 1962, titled ''Method of Edge Waves in the Physical Theory of Diffraction'', Soviet Radio, Moscow, 1962. In 1971 this book was translated into English with the same title by U.S. Air Force, Foreign Technology Division.National Air Intelligence Center, Wright-Patterson AFB, OH, 1971. Technical Report AD 733203, Defense Technical Information Center of USA, Cameron Station, Alexandria, VA, 22304-6145, USA The theory played a critical role in the design of American stealth-aircraft F-117 and B-2.Browne, M.W. "Two rival designers led the way to stealthy warplanes", New York Times, Sci. Times Sec., May 14, 1991.Browne, M.W. "Lockheed credits Soviet theory in design of F-117", Aviation Week Space Technology p. 27, December 1991.Rich, Ben and L. Janos, ''Skunk Works'', Little Brown, Boston, 1994. Equations outlined in the paper quantified how a plane's shape would affect its detectability by radar, its radar cross-section (RCS). This was applied by Lockheed in computer simulation to design a novel shape they called the "Hopeless Diamond", a wordplay on the Hope Diamond, securing contractual rights to produce the F-117 Nighthawk starting in 1975. In 1977 Lockheed produced two 60% scale models under the Have Blue contract. The Have Blue program was a stealth technology demonstrator that lasted from 1976 to 1979. The success of Have Blue led the Air Force to create the ''Senior Trend''(F-117A ''Senior Trend'' )("Senior Trend" ). ''Vectorsite.net'', 1 April 2008. program which developed the F-117.」の詳細全文を読む スポンサード リンク
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